Nato's vulnerable convoys

Zafar Jaspal, a security analyst in Pakistan, spoke to Al Jazeera in the wake of a deadly attack on a Nato convoy near Islamabad that was transporting supplies across the border into Afghanistan.

At least six drivers were killed in the raid of June 8, with a group of men armed with guns and grenades striking in the middle of night and torching more than 50 lorries, in the process destroying millions of dollars worth of fuel, food and other supplies.

Attacks on Nato convoys are not unusual in Pakistan, but what has got security forces worried this time is that the attack took place on the outskirts of the federal capital.